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Dental Tribune Middle East & Africa Edition | 5/2016 lab tribune 2 ◊Page1 Clinical examination and treatment planning The first part of the oral rehabilita- tion process involved a clinical ex- amination in which the facial and dental conditions were analyzed. Thisinvestigationshowedasubstan- tially reduced vertical dimension of occlusion. The patient was missing 14 permanent teeth. Furthermore, several deciduous teeth were still in place. Tooth 36 had been destroyed by caries, making its extraction in- evitable. Inordertoprovidethedentaltechni- cian with the information required for waxing up a restoration, details related to the vertical dimension of occlusion and facebow records must be supplied in addition to the impression.Iftheverticaldimension of occlusion needs to be increased, the correct centric position has to be evaluated first. In this case, an ante- rior Lucia jig made of a thermoplas- tic material was used as a registra- tion aid (Fig. 2). A facebow was used to establish the relationship of the maxillaryjawtothehorizontalrefer- ence plane or bipupillary line. In the fabricationofextensiverestorations, the protrusive and the laterotrusive positions have to be recorded in or- der to make any necessary adjust- ments in the articulator. An addition silicone, for example, Virtual® CAD- bite can be used for this purpose. In most cases, this type of material produces faster and more accurate results than wax. When wax is used for bite-taking, the patient has to be shown how to move into the protru- siveorlaterotrusiveposition.Experi- ence has shown that it is easier to let the patients produce these move- ments of their own accord and stop them when they arrive at the “right” position (Fig. 3). Virtual CADbite is injected while the teeth are in this closedposition. Wax-upandmock-up The following minimum documen- tation was required for the fabrica- tion of the wax-up: precision im- pressions of the upper and lower jaw, a facebow transfer record, a centric bite record in wax with the predetermined vertical dimension of occlusion, portrait pictures of the patient as well as close-up pictures of the situation when the patient is smiling. This information was used to build up the restoration in wax and bring the teeth into their ideal functional and esthetic position. Furthermore, the occlusal plane and the Spee’s curve were adjusted (Fig. 4). For the purpose of checking the laboratory work intraorally, a mock- up of the wax-up was made (Telio® CS C&B) (Fig. 5). All the functional and esthetic parame ters were then checkedinthepatient’smouth. This stage of the treatment is very important for many reasons. Pa- tients are given the opportunity to actively participate in designing their new smile, which is a very mo- tivating experience. In addition, the functional wax-up, the maximum intercuspation, the new vertical di- mension and the protrusive and lat- erotrusive movements can be tested in a realistic situation. Moreover, the mock-up serves as a model for the provisional restoration. Therefore, it shouldbeproducedwiththehighest of accuracy. Once the patient is com- pletely satisfied with the proposed result and the mock-up fulfils all the clinical criteria, the actual treatment canbegin. Preliminarytreatment At present, the preparatory meas- ures for minimally invasive proce- duresandthetopicoftoothprepara- tion are receiving a lot of attention. Nevertheless, there are some other aspectsthatshouldnotbeneglected. For example, the properties of the materials used strongly influence the result. State-of-heart materials are offering increasingly sophisti- cated solutions. Before using any new materials, it is important to learn more about the application recommendations of the manufac- turer. Excellent planning and a care- fullycraftedmock-upwillreducethe preparations needed for the fabrica- tion of the final restoration. With the help of the mock-up, for example, the teeth can be suitably prepared for veneers or even crowns. The use of optical appliances such as dental loupes and microscopes also makes workeasierandmoreaccurate. In the present case, the teeth were first cleaned very thoroughly. The necessary extractions were per- formedandonetoothwasendodon- tically treated. Then the teeth were prepared and readied for the pros- thetic treatment (Figs 6 and 7). The long-term temporary was fabricated using CAD/CAM equipment. There- fore, the wax-up was digitized with thehelpofalaboratoryscanner.This information provided a basis for the computer-aided design of the pro- visional. The CAD/ CAMfabricated provisional made of tooth-coloured composite (Telio CAD) also served as a test object or blueprint during the healing process. Its function and esthetics were closely examined and adjustedindetail(Fig.8). Fabricationofthepermanent restoration The final prosthetic phase started after the long-term temporary had been worn for an adequate period of time. Before impression-taking, the teeth were prepared again and polished. It is very important to transfertheverticaldimensionofoc- clusion and the information about thetooth-to-toothrelationshipfrom the provisional to the final resto- ration with great care. The “cross- mounting” technique is suitable for this purpose. This method entails first making a bite record of the pre- pared teeth in the upper and lower jaw.Subsequently,asecondrecordis taken of the provisional restoration in the upper jaw and the prepared teeth in the lower jaw. A third record is captured of the prepared teeth in the upper jaw and the provisional restorationinthelowerjaw. The dental technician required the following minimum information in order to fabricate the restoration: precision impressions of the upper andlowerjaw,precisionimpressions of the provisionals, a facebow trans- fer record and three bite records (“cross-mounting”), and recent por- trait pictures of the patient wearing the provisionals as well as photos of thepatientsmiling. The aim at this stage was to “copy” the shape and occlusal plane of the provisionals and to accurately transfer this information to the fi- nal restoration. For this purpose, the master casts were placed in the ar- ticulator after the “cross-mounting” process. Since the final situation had beensuccessivelyattainedbymeans of the provisionals, the frameworks couldbefabricatedrelativelyeasily. As a result of using the CAD/CAM approach, the final restoration could be visualized, modified and/ or duplicated with the assurance that all the design guidelines would be observed. The Wieland Precision Technology (WPT, Naturns, Italy) milling centre was responsible for fabricating the frameworks for the metal-ceramic restorations in the posterior region as well as the ziron- ciumoxideframeworkfortheupper anteriorteeth(Fig.9).Theframework was tried in to confirm the correct fit of the restoration. Most of the inac- curaciesthatusuallyoccuraredueto errors made during impression tak- ing,castingormodelfabrication.The veneers for the lower teeth were also made with the assistance of digital technology. They were subsequently pressed with lithum discilicate glass- ceramic(IPSe.max®). The metal frameworks were ve- neeredwiththenewPFMsystemIPS Style®. It allowed us to achieve the desired natural-looking, translucent shade without having to sacrifice on brightness. The IPS Style ceramic offers a major advantage in that it can be optimally combined with IPS e.maxCeram.Asaresult,theveneers on the metal frameworks could be optimally adjusted to the bridge in the upper jaw. After the first bake, the restoration was tried in. At this stage, the need for smaller adjust- ments of the ceramic was identified. Subsequently, the restorations were glaze firedandpolished.The veneers were completed by firing on a thin layer of IPS e.max Ceram A1, fol- lowedbyathinglazelayer(Fig.10). Before the restorations were seated, the teeth were cleaned and a rubber dam (OptraDam® Plus) was placed. Luting composites such as Vari- olink® Esthetic are suitable for the placementofthistypeofrestoration. Thiscementexhibitsexcellentadhe- sive properties and clinically ben- eficial characteristics such as easy removal of excess and long-term shade stability. The system offers an additional advantage in that the shades of the dual-curing (DC) and the light-curing (LC) luting compos- ite are the same. The DC cement is used for crowns and bridges (Fig. 11) and the LC cement for veneers. Fur- thermore,weusedMonobond®Etch & Prime to condition the veneers (adhesive cementation). After gentle sandblasting, the zirconium oxide andmetal-ceramicrestorationswere prepared for placement by applying Monobond Plus. Glycerine gel (Liq- uidStrip)wasappliedinordertopre- vent the formation of an inhibition layer. The final result completely satisfied all the parties involved. The situation which was established dur- ing the treatment phase was exactly transferred to the final restoration (Figs12aandb). Conclusion In extensive cases, it is particularly importanttodevelopawellthought- out plan including all the treatment steps, which needs to be carefully followedatalltimes.Inthedescribed case, various ceramic materials were cleverly combined to produce a har- moniousresult.Excellentcommuni- cation between the dentist and the dentaltechniciantogetherwithwell- coordinated state-of-the-art materi- als systems provided the basis for thishighlysatisfactoryoutcome. Fig. 4:Wax-up:ideal functional and esthetic position and adjust- edocclusalplaneandSpee’scurve Fig.6:Thepreparedupperanterior teeth Fig.5:Mock-upfabricatedwiththehelpof thewax-upfor thein- traoralexaminationof thefunctionalandestheticcomponents Fig.7:Thepreparedloweranterior teeth Fig. 8: The CAD/CAM-fabricated long-term provisional (Telio CAD)in themouth Fig. 10: Metal-ceramic posterior bridge (IPS Style); all-ceramic upper anterior bridge (IPS e.max Ceram); veneers on the lower anterior teeth(IPSe.maxPress) Fig.12a:Thepermanentlyplacedrestorationin themouth… Fig. 12b: … and a portrait picture of the patient. Fig.9:TheCAD/CAM-fabricatedframeworkon themodelof the upperjaw Fig. 11: Upper anterior restoration after placement with an es- theticlutingcomposite(VariolinkEstheticDC) DrMarkoJakovac AssociateProfessor Department ofFixed Prosthodontics SchoolofDentalMedicine UniversityofZagreb Gunduliceva5 1000Zagreb,Croatia jakovac@sfzg.hr MicheleTemperani LaboratorioOdontotecnica Temperani ViaLivorno54\2 50142Florence,Italy micheletemperani@gmail.com